| Author | Tunyanuch Uakaroonchaikul |
| Call Number | AIT Thesis no.FB-07-09 |
| Subject(s) | Onions--Drying
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. FB-07-09 |
| Abstract | The vacuum infrared-dryer was developed and evaluated by its performance during drying of red onion slices. The infrared radiative drying of red onion slices have been studied at different infrared radiation intensity and level of pressure. Experiments were conducted in three levels of infrared radiation intensity - 300, 400 and 500 watt and two levels of pressure - 500 and 760 mmHg, under 6 drying conditions. Drying rate, quality of dried red onion and quercetin content in dried red onion were investigated. Hot air drying at 60°C was applied to dry red onion as a control. Vacuum infrared drying showed the highest drying rate in comparison to infrared drying without vacuum and hot air drying. Two mathematical models in drying equation i.e. Newton's and Page's model had been developed. The results were compared to their goodness of fit in term of R2 and RMSE. Page's model was represented in order to describe the drying behavior of red onion slices under infrared drying with and without vacuum. The qualities of dried red onion i.e. rehydration and color were also examined. The vacuum infrared drying at 500 watt presented the optimum intensity in qualities of dried red onion for preservation and extends the shelf life, reduction in weight and volume, minimizing packaging, storage and transportation costs. Quercetin content in dried red onion was analyzed by HPLC. The result showed that infrared drying at 400 watt level gave the highest quercetin content which was over 3.0 times more than hot air drying at 60°C. Antioxidant activity of quercetin extracted sample from dried red onion was investigated on lard. The result showed that lard with quercetin extract could decrease 44.45% of peroxide value comparing to pure lard. |
| Year | 2007 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. FB-07-09 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Athapol Noomhorm; |
| Examination Committee(s) | Rakshit, Sudip Kumar;Salokhe, Vilas M.; |
| Scholarship Donor(s) | RTG Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2007 |